#ifndef MUDUO_BASE_TYPES_H
#define MUDUO_BASE_TYPES_H

#include <stdint.h>
#ifdef MUDUO_STD_STRING
#include <string>
#else  // !MUDUO_STD_STRING
#include <ext/vstring.h>
#include <ext/vstring_fwd.h>
#endif

#ifndef NDEBUG
#include <assert.h>
#endif

///
/// The most common stuffs.
///
namespace muduo
{

#ifdef MUDUO_STD_STRING
	using std::string;
#else  // !MUDUO_STD_STRING
	typedef __gnu_cxx::__sso_string string;
#endif

	// Taken from google-protobuf stubs/common.h
	//
	// Protocol Buffers - Google's data interchange format
	// Copyright 2008 Google Inc.  All rights reserved.
	// http://code.google.com/p/protobuf/
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are
	// met:
	//
	//     * Redistributions of source code must retain the above copyright
	// notice, this list of conditions and the following disclaimer.
	//     * Redistributions in binary form must reproduce the above
	// copyright notice, this list of conditions and the following disclaimer
	// in the documentation and/or other materials provided with the
	// distribution.
	//     * Neither the name of Google Inc. nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	// Author: kenton@google.com (Kenton Varda) and others
	//
	// Contains basic types and utilities used by the rest of the library.

	//
	// Use implicit_cast as a safe version of static_cast or const_cast
	// for upcasting in the type hierarchy (i.e. casting a pointer to Foo
	// to a pointer to SuperclassOfFoo or casting a pointer to Foo to
	// a const pointer to Foo).
	// When you use implicit_cast, the compiler checks that the cast is safe.
	// Such explicit implicit_casts are necessary in surprisingly many
	// situations where C++ demands an exact type match instead of an
	// argument type convertable to a target type.
	//
	// The From type can be inferred, so the preferred syntax for using
	// implicit_cast is the same as for static_cast etc.:
	//
	//   implicit_cast<ToType>(expr)
	//
	// implicit_cast would have been part of the C++ standard library,
	// but the proposal was submitted too late.  It will probably make
	// its way into the language in the future.
	template<typename To, typename From>
		inline To implicit_cast(From const &f)
		{
			return f;
		}

		// When you upcast (that is, cast a pointer from type Foo to type
		// SuperclassOfFoo), it's fine to use implicit_cast<>, since upcasts
		// always succeed.  When you downcast (that is, cast a pointer from
		// type Foo to type SubclassOfFoo), static_cast<> isn't safe, because
		// how do you know the pointer is really of type SubclassOfFoo?  It
		// could be a bare Foo, or of type DifferentSubclassOfFoo.  Thus,
		// when you downcast, you should use this macro.  In debug mode, we
		// use dynamic_cast<> to double-check the downcast is legal (we die
		// if it's not).  In normal mode, we do the efficient static_cast<>
		// instead.  Thus, it's important to test in debug mode to make sure
		// the cast is legal!
		//    This is the only place in the code we should use dynamic_cast<>.
		// In particular, you SHOULDN'T be using dynamic_cast<> in order to
		// do RTTI (eg code like this:
		//    if (dynamic_cast<Subclass1>(foo)) HandleASubclass1Object(foo);
		//    if (dynamic_cast<Subclass2>(foo)) HandleASubclass2Object(foo);
		// You should design the code some other way not to need this.

	template<typename To, typename From>     // use like this: down_cast<T*>(foo);
		inline To down_cast(From* f)                     // so we only accept pointers
		{
		  // Ensures that To is a sub-type of From *.  This test is here only
		  // for compile-time type checking, and has no overhead in an
		  // optimized build at run-time, as it will be optimized away
		  // completely.
			if (false)
			{
				implicit_cast<From*, To>(0);
			}

#if !defined(NDEBUG) && !defined(GOOGLE_PROTOBUF_NO_RTTI)
			assert(f == NULL || dynamic_cast<To>(f) != NULL);  // RTTI: debug mode only!
#endif
			return static_cast<To>(f);
		}

}

#endif
